Composite sheet material and method for forming the same

ABSTRACT

A composite sheet material and method for forming the same is provided that includes a substrate, a matrix, and a cover sheet. The substrate has a first face surface, a second face surface, and a plurality of edges, and includes a thermoplastic material. The matrix is attached to the substrate. The matrix includes a support component having a first melting point, and a thermoplastic component having a second melting point. The second melting point is less than the first melting point. The cover sheet imparts one or more surface characteristics to the composite sheet material during thermo-pressure formation of the composite sheet material.

This application is a continuation-in-part of U.S. patent applicationSer. No. 13/605,598 filed Sep. 6, 2012.

BACKGROUND OF THE INVENTION

1. Technical Field

This invention relates generally to composite sheet materials thatinclude a nonwoven or woven fabric and a thermoplastic material, to amethod of forming the same, and to products that include such acomposite sheet material.

2. Background Information

Composite materials that consist of a thermoplastic nonwoven materialwith a thermoplastic material are known in the public. The outersurface(s) of such composite products, however, typically have poorscratch resistance, poor abrasion qualities, poor stain resistance, andpoor color brilliance, are difficult to adhere to, have undesirableappearance characteristics (e.g., uneven surface finish), and do notaccept pigment or print well.

It would, therefore, be desirable to have a composite product thatovercomes the above shortcomings and provides additional enhancements.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, a composite sheetmaterial is provided that includes a substrate, a matrix, and a coversheet. The substrate has a first face surface, a second face surface,and a plurality of edges, and includes a thermoplastic material. Thematrix is attached to the substrate. The matrix includes a supportcomponent having a first melting point, and a thermoplastic componenthaving a second melting point. The second melting point is less than thefirst melting point. The cover sheet imparts one or more surfacecharacteristics to the composite sheet material during thermo-pressureformation of the composite sheet material.

According to another aspect of the present invention, a method offorming a composite sheet material is provided. The method includes thesteps of: a) providing a substrate having a first face surface, a secondface surface, and a plurality of edges, and which substrate includes athermoplastic material; b) forming a matrix from a sheet of a supportcomponent and a sheet of a thermoplastic component, wherein the supportcomponent has a first melting point and the thermoplastic component hasa second melting point, and the second melting point is less than thefirst melting point; c) positioning the substrate and the matrix suchthat the matrix is contiguous with the first face surface of thesubstrate; and d) laminating the substrate and matrix together in athermo-pressure process to form the composite sheet material.

According to another aspect of the present invention, a method offorming a composite sheet material is provided. The method includes thesteps of: a) providing a substrate having a first face surface, a secondface surface, and a plurality of edges, and which substrate includes athermoplastic material; b) forming a matrix by extruding a multilayerthermoplastic component onto a support component, wherein the supportcomponent has a first melting point and the thermoplastic component hasa second melting point, and the second melting point is less than thefirst melting point; c) positioning a sheet of the substrate and a sheetof the matrix such that the matrix is contiguous with the first facesurface of the substrate; and d) laminating the substrate and matrixtogether in a thermo-pressure process to form the composite sheetmaterial.

According to another aspect of the present invention, a composite sheetmaterial matrix is provided that includes a support component and athermoplastic component. The support component has a first meltingpoint. The thermoplastic component has a plurality of layers. Thethermoplastic component has a second melting point, and the secondmelting point is less than the first melting point.

According to another aspect of the present invention, a composite sheetmaterial is provided that includes a substrate and a matrix. Thesubstrate includes a first face surface, a second face surface, aplurality of edges, and a thermoplastic material. The matrix is attachedto the substrate. The matrix includes a support component having a firstmelting point, a thermoplastic component having a second melting point,and a secondary thermoplastic component having a third melting point.The second melting point is less than the first melting point. The thirdmelting point is equal to or less than the first melting point.

According to another aspect of the present invention, a side skirtassembly adapted to be mounted to a tractor trailer is provided. Theside skirt assembly includes a support frame and a side skirt panel. Thesupport frame is configured for attachment to the tractor trailer. Theside skirt panel is attached to the support frame. The side skirt panelis a composite sheet material that has a length and a width. Thecomposite sheet material includes a substrate, a matrix, and a coversheet. The substrate includes a thermoplastic material. The matrix isattached to the substrate. The matrix includes a support componenthaving a first melting point, and a thermoplastic component having asecond melting point, and the second melting point is less than thefirst melting point. The cover sheet is configured to impart one or moresurface characteristics to the composite sheet material during athermo-pressure formation of the composite sheet material. The sideskirt assembly is configured so that the width of the side skirt panelis substantially vertically positionable on a side of the tractortrailer, and the length of the side skirt panel extends along the lengthof the tractor trailer.

According to another aspect of the present invention, a panel for atractor trailer box container having a frame is provided. The panelincludes a composite sheet material and has a length and a width. Thecomposite sheet material includes a substrate, a matrix, and a coversheet. The substrate includes a thermoplastic material, and the matrixis attached to the substrate. The matrix includes a support componenthaving a first melting point, and a thermoplastic component having asecond melting point, and the second melting point is less than thefirst melting point. The cover sheet is configured to impart one or moresurface characteristics to the composite sheet material during athermo-pressure formation of the composite sheet material. The compositesheet material panel is configured for attachment to the frame of thetractor trailer box container frame.

These and other objects, features and advantages of the presentinvention will become apparent in light of the detailed description ofthe invention provided below, and as illustrated in the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of an embodiment of the present compositesheet material, including a backing layer and a cover sheet.

FIG. 1A is a diagrammatic view of an embodiment of the present compositesheet material.

FIG. 1B is a diagrammatic view of an embodiment of the present compositesheet material.

FIG. 2 is a diagrammatic view of an embodiment of the present compositesheet material, illustrating the sheet material after formation.

FIG. 3 is a diagrammatic view of an embodiment of the present compositesheet material, including a matrix having a multilayer thermoplasticcomponent.

FIG. 4 is a diagrammatic exploded view of a stack up of thethermoplastic component, the support component, and the substrate of anembodiment of the present composite sheet material.

FIG. 5 is a diagrammatic view of an embodiment of the present compositesheet material, including a removable cover layer partially peeled awayfrom the matrix.

FIG. 6 is a diagrammatic view of an embodiment of the present compositesheet material including a matrix having a secondary thermoplasticmaterial.

FIG. 7 is a diagrammatic illustration of a configuration formanufacturing an embodiment of the present composite sheet material.

FIG. 8 is a diagrammatic illustration of a configuration formanufacturing an embodiment of the present composite sheet material.

FIG. 9 is a diagrammatic illustration of a configuration formanufacturing an embodiment of the present composite sheet material.

DESCRIPTION OF THE INVENTION

Referring to FIG. 1, the present composite sheet material 10 includes asubstrate 12 and a matrix 14, and in some embodiments a cover sheet 16and a backing layer 18.

The substrate 12 can be formed as a sheet product having a first facesurface 20, a second face surface 22, and a plurality of edges. Thesubstrate 12 includes one or more thermoplastic materials such as, butnot limited to, polypropylene (PP), polylactic acid (PLA), polyethyleneterephthalate (PET), polybutylene terephthalate (PBT), polyethylene(PE), polyamide (PA), Polyphenylene ether/oxide (PPO), Polycarbonates(PC), Polyphenylene sulfide (PPS), Acrylonitrile butadiene styrene(ABS), polyvinyl chloride (PVC), Polyoxymethylene (“POM”), or “Acetal”,or as the DuPont product Delrin®), and copolymers thereof, typically infiber or strand or extruded form. The substrate may also include (e.g.have an internal or external layer of) thermoset materials such asunsaturated polyesters, epoxy, vinyl esters, polyurethanes, phenolic,silicones, melamine, polystyrene. The substrate 12 may also includenon-thermoplastic materials such as cotton, wood pulp, rayon, bagasse,phenolic, wool, fiberglass, flax, bamboo, carbon fiber, aramid, etc.,and combinations thereof, also typically in fiber, chopped fiber, woven,stitched, braided or continuous strand form; e.g., for reinforcingpurposes, etc. Materials within the substrate 12 may be made in a wovenor non-woven form, or using random laid fibers. In those embodimentswhere the substrate 12 is nonwoven, the substrate 12 can be made usingwetlaid, pointbond, spunbond, spunlace, airlaid, needle punched ormeltblown processes, or thermal bond processes, or combinations thereof.The substrate 12 may alternatively include a bicomponent nonwoven havingtwo different polymers arranged within a web. A preferred bicomponentnonwoven is a continuous filament spunbond type bicomponent non-woven.Bicomponent nonwovens utilize a sheath and core construction, wherein acore filament made of one resin is completely surrounded by a sheath ofa different resin. The performance of the bicomponent nonwoven benefitsfrom the characteristics (e.g., strength, flexibility, etc.) of both thesheath and core materials. Many polymer materials can be used in abicomponent nonwoven, including but not limited to, polyester,polypropylene, polyethylene, nylon, and polylactic acid. An example ofan acceptable bicomponent nonwoven is one having polypropylene orpolyethylene sheath and a polyester core. The substrate 12 may include asingle layer of a material, or may be formed of multiple layers of thesame material, or multiple layers of more than one type of material. Thesubstrate 12 may include one or more additives, including those thatfunction as ultraviolet (UV) inhibitors and thermal stabilizers, thosethat make the substrate fire-resistant, and other additives such aspigments, wetting agents, anti-microbial agents, hydrophilic agents, andhydrophobic agents. The substrate 12 may also include one or moreadditives, including those that function as ultraviolet (UV) inhibitorsand thermal stabilizers, those that make the composite sheet material 10fire-resistant, and other various additives such as pigments, silicones,additives that improve stain resistance and cleanability (e.g., PTFE andother fluoropolymers), wetting agents, anti-microbial agents, anti-gasfade agents (e.g., chemical resistance agents), hydrophilic agents,hydrophobic agents. In those embodiments where a portion, or all, of thesubstrate 12 is extruded, the substrate 12 may also include process aidsto improve extrusion surface uniformity. The substrate 12 may alsoinclude one or more of the following additives: biodegradable additives,grease resistant additives, antioxidant additives, slip agents,additives to minimize or eliminate static electricity, and conductiveand/or semi-conductive particles or fibers. The characteristics (e.g.,fire-resistance, UV inhibitors, etc.) of the various additives andcomponents described above as potential constituents within thesubstrate 12, are not limited to the substrate 12, but may also bedescribed as being a part of the composite sheet material 10 of whichthe thermoplastic component is a portion. The substrate 12 is not,however, limited to these additives.

The materials used to create the substrate 12 may be arranged inparticular orientations to give the substrate 12 desirable mechanicalcharacteristics. For example, in those substrate 12 embodiments thatutilize fibrous materials, the fibers can be oriented to providedesirable stiffness, impact resistance, flexibility, etc. In thosesubstrate 12 embodiments that include more than one layer, the contentand orientation of the different layers can be also selected andarranged to enhance the mechanical characteristics; e.g., thermoplasticmaterials that enhance the impact resistance, flex strength, and/ortensile strength of the substrate 12, and glass or other reinforcingfibers that enhance the stiffness of the substrate 12.

Referring to FIG. 1A, in some embodiments the substrate 12 may include aveiling layer 40 that includes a higher temperature melt fiber componentand a lower temperature melt fiber component. The veiling layer 40 isattached to the substrate surface contiguous with the matrix 14. Anexample of an acceptable material for the veiling layer 40 is a needlepunched non-woven material including a higher temperature melt fibercomponent and a lower temperature melt fiber component. The highertemperature melt component has a melting temperature that is higher thanthat of the lower temperature melt component. An example of a veilinglayer 40 is a substrate having about 50% higher temperature melt fibersconsisting of polyester fibers and about 50% lower temperature meltfibers consisting of polypropylene fibers. The components arepreferably, but not necessarily, uniformly distributed throughout theveiling layer 40. A needle-punched non-woven material provides desirableuniform distribution of the fibers in the veiling layer 40, includinginterstitial voids within the veiling layer 40 that increase theformability (during formation of the composite sheet material 10) andveiling performance of the veiling layer 40 in the finished compositesheet material 10. The veiling layer 40 may alternatively include abicomponent nonwoven having two different polymers arranged within aweb. A preferred bicomponent nonwoven is a continuous filament spunbondtype bicomponent non-woven. Bicomponent nonwovens utilize a sheath andcore construction, wherein a core filament made of one resin iscompletely surrounded by a sheath of a different resin. Many polymermaterials can be used in a bicomponent nonwoven, including but notlimited to, polyester, polypropylene, polyethylene, nylon, andpolylactic acid. An example of an acceptable bicomponent nonwoven is onehaving polypropylene or polyethylene sheath and a polyester core. Theterm “veiling” is used herein to describe the ability of the veilinglayer 40 to prevent surface planar irregularities (e.g., planardiscontinuities such as bumps, peaks, depressions, etc.) of the surfaceof the substrate layer contiguous with the veiling layer fromtelegraphing through the veiling layer 40. The term “telegraphing” isused herein to describe when planar irregularities of the substratesurface in contact with a first surface of a layer are detectable in asecond opposite surface of the layer, when the substrate and layer arein intimate contact with one another (e.g., pressed together). Thedegree to which the planar irregularities are detectable on the secondopposite side of the layer equates to the degree to which the planarirregularities “telegraph” through the layer. Within the thickness ofthe present veiling layer 40, some or all of the aforesaid planarirregularities of the surface of the substrate layer contiguous with theveiling layer 40 are received within, or filled by, the material of theveiling layer 40, consequently substantially mitigating the degree towhich those planar irregularities will telegraph through the veilinglayer 40 to the opposite surface of the veiling layer 40. As a result,the veiling layer 40 increases the flatness (as that term is describedbelow) of the surface to which the matrix 14 is attached, which in turnincreases the flatness of the outer surface of the composite sheetmaterial 10. The veiling layer 40 is not limited to the materialidentified in the above 50/50 fiber example. In alternative examples,the veiling layer 40 may comprise a single material type, or more thantwo material types, etc.

The matrix 14 is attached to first face surface 20 of the substrate 12.The matrix 14 includes a woven or nonwoven support component 24 and athermoplastic component 26. In some embodiments, the matrix includes asecondary thermoplastic component 27.

The support component 24 substantially consists of a primary material(or combination of materials) having a melting point, and for purposesof describing the present invention the support component 24 will bedescribed as having a melting point equal to that of the primarymaterial. As will be described below, the thermoplastic component 26 hasa melting point which is lower than the melting point of the supportcomponent 24. An example of an acceptable material for the supportcomponent 24 is a nonwoven polyester (which has a melting point in therange of approximately 250-300 degrees centigrade; 250° C.-300° C.)formed by a spun bond process. The support component 24 is not limitedto polyester, and can be formed from a variety of materials having amelting point that is higher than that of the thermoplastic component26. In those embodiments where it is desirable to have a composite sheetmaterial 10 with a flat exterior surface, the support component 24 maybe formed using a spunlace or needled nonwoven process that utilizesfibers that are short; e.g., relative to continuous fibers used in aspun bond process. In the spunlace process, fibers are spun and thendirectly dispersed into a web by deflectors or can be directed with airstreams. Prior art techniques for consolidating fibers in a web includemechanical bonding, which entangles the fibers to give strength to theweb. Well-known mechanical bonding techniques for creating bondednonwovens include needlepunching and hydroentanglement. The latter useshigh-speed jets of water to strike a web so that the fibers knot aboutone another. Needlepunching is a similar process that uses mechanicalneedles perforating the web to create the desired knotted fiberstructure. In some instances (i.e., the spunbonding technique),synthetic polymers are extruded into filaments and directly formed intowebs which selfbond under elevated heat and/or pressure to produce thefinal fabric. In other instances, the fibrous web is fluid rearrangedand then resin binder may be added to form a useful, coherent nonwovenfabric. The shorter fibers typically result in a flatter surface thanmight be produced in a process using longer fibers (e.g., a spunbondprocess that utilizes continuous fibers that are point bonded). Theterms “flat” or “flatness” are used herein to describe the quality ofsurface as being an even surface without risings or depressions (e.g.,planar irregularities). With the acknowledgement that no surface isperfectly flat, the terms “flat” and “flatness” may be used herein torefer to the relative amount of risings and/or depressions in a surface;e.g., embodiments of the present composite surface, as described herein,can be formed to have a flatness that is greater than similar prior artcomposites, and in many instances will appear perfectly flat to thenaked eye. The shorter fibers provide desirable uniformity and alsoprovide better resistance to delamination, due to the omnidirectionalorientation of the fibers (e.g., oriented in any of the X, Y, and Zaxes, and combinations thereof). The continuous fibers used within aspun bond process tend to extend predominantly within a single plane(e.g., X-Y plane) and consequently are more susceptible to delaminationunder certain circumstances. The support component 24 is not limited toany particular formation process, however. Alternatively, the supportcomponent may take the form of an apertured fabric (sometimes referredto as “perforated fabric”). An apertured nonwoven web may be formed bypassing an unbonded fiber web through a nip formed by a set ofintermeshing rolls which have three-dimensional projections to displacefibers away from the projections, forming apertures which conform to theoutside contours of the base of the projections in the web. Theapertured web is subsequently bonded to impart permanent physicalintegrity. A person of skill in the art will recognize, however, thatapertured nonwovens may be made by other processes as well. An advantageof using an apertured nonwoven is that it can provide a superior bondingsurface within the matrix due to additional surface area provided by theapertures. The support component 24 may also be formed using fibers thatare pretreated, coated, or saturated with a binder to provide thesupport component with desirable properties. Alternatively, the fiberswithin the nonwoven may be subsequently treated, coated or saturatedwith the binder to provide the aforesaid desirable properties.Non-limiting examples of such a binder include a polyurethane (e.g.,BASF Astacin®), butadiene (e.g., BASF Luron®), or an acrylic that is adispersion mainly of polyacrylic and polymethacrylic esters, usuallyproduced by radical initiated emulsion polymerization of the unsaturatedmonomers (e.g., Celanese Emulsions Nacrylic® 217A, which is aself-crosslinking acrylic polymer emulsion, or Celvol 523) can be usedto further enhance adhesion and strength. The embodiments of the supportcomponent 24 that use a binder are not, however, limited to theseexamples. The support component 24 may alternatively include abicomponent nonwoven having two different polymers arranged within aweb. A preferred bicomponent nonwoven is a continuous filament spunbondtype bicomponent non-woven. Bicomponent nonwovens utilize a sheath andcore construction, wherein a core filament made of one resin iscompletely surrounded by a sheath of a different resin. Many polymermaterials can be used in a bicomponent nonwoven, including but notlimited to, polyester, polypropylene, polyethylene, nylon, andpolylactic acid. An example of an acceptable bicomponent nonwoven is onehaving polypropylene or polyethylene sheath and a polyester core. Insome embodiments, the support component 24 may also be calendered toincrease the density and flatness of the support component 24, and/or tofacilitate bonding of the fibers together to increase the supportcomponent's resistance to delamination.

Examples of acceptable support component 24 materials include, but arenot limited to, polyester (PET or PBT), nylon (Polyamide),polyphenylsulfide (PPS), aromatic polyamide (both meta aramid and paraaramid), fiberglass, PTFE, wool, carbon fiber, Alumina/Silica,polyimide, polypropylene, polyethylene, cellulose, rayon, and viscose,or combinations thereof.

The thermoplastic component 26 substantially consists of, but is notlimited to, configurations of the following materials (and co-polymersthereof) having a melting point lower than that of the support component24 material: polypropylene (PP), polyethylene (PE), polyethyleneterephthalate (PET), low-density polyethylene (LDPE), polyurethane (PU),polyamide (PA), polyamide-imide (PAI), ionomer (e.g., Surlyn®, SurlynReflections®—which is an ionomer with a polyamide—, etc.), acrylic,metallocenes (i.e., a type of thermoplastic material), etc. The highermelting point of the support component 24 material allows thethermoplastic component 26 to melt and at least partially migratethrough the support component 24 without the support component 24melting during the initial formation of the matrix (and in someembodiments also migrate through and into contact with the substrate 12when the substrate 12 and the matrix 14 are joined to one another underan elevated heat and pressure process). Consequently, the supportcomponent 24 helps to define the matrix 14 relative to the substrate 12.Note that certain polymers may be available in a plurality of differentforms, and collectively they may have a wide range of melting points. Insome instances, it may be possible to use a first variation of aparticular thermoplastic material for the support component 24 and asecond variation of the same thermoplastic material for thethermoplastic component 26, provided the two variations havesufficiently different melting points. The thermoplastic component 26may also include one or more additives, including those that function asultraviolet (UV) inhibitors and thermal stabilizers, those that make thecomposite sheet material 10 fire-resistant, and other various additivessuch as pigments, silicones, additives that improve stain resistance andcleanability (e.g., PTFE and other fluoropolymers), wetting agents,anti-microbial agents, anti-gas fade agents (e.g., chemical resistanceagents), hydrophilic agents, hydrophobic agents. In those embodimentswhere a portion, or all, of the thermoplastic component 26 is extruded,the thermoplastic component 26 may also include process aids to improveextrusion surface uniformity. The thermoplastic component 26 may alsoinclude one or more of the following additives: biodegradable additives,grease resistant additives, antioxidant additives, slip agents,additives to minimize or eliminate static electricity, and conductiveand/or semi-conductive particles or fibers. The characteristics (e.g.,fire-resistance, UV inhibitors, etc.) of the various additives andcomponents described above as potential constituents within thethermoplastic component 26, are not limited to the thermoplasticcomponent 26, but may also be described as being a part of the compositesheet material 10 of which the thermoplastic component 26 is a portion.

The thermoplastic component 26 may be applied to the support component24 as a coating. The thermoplastic component 26 coating initiallyresides on a face surface of the support component 24, and/or may atleast partially saturate the substrate 12 prior to the composite sheetmaterial 10 formation processes (e.g., thermo-pressure lamination). Thecoating may be applied to the support component 24 using an extrusionprocess, or any other known process operable to apply the thermoplasticcomponent 26 as a coating. In one example of an extrusion process, boththe thermoplastic component 26 and the support component could be formedtogether in a single pass extrusion process. Alternatively, thethermoplastic component 26 may initially assume a sheet form disposed onone side of the support component 24. The one or more sheets of thethermoplastic component 26 may be joined (e.g., laminated) to thesupport component 24 to form the matrix, and subsequently the matrix 14can be attached to the substrate 12. Alternatively, the supportcomponent 24 and the one or more sheets of the thermoplastic component26 may be stacked together with the substrate 12, and all joinedtogether simultaneously; e.g., in an elevated heat and pressure process.Post matrix or composite sheet formation, a sufficient amount ofthermoplastic component 26 resides on the exterior surface 28 of thematrix 14 to form a substantially uninterrupted surface consisting ofthe thermoplastic component 26, and some amount of thermoplasticcomponent 26 is in contact with the first face surface 20 of thesubstrate 12 as can be seen in FIG. 2.

Regardless of its form (coating, sheet, etc.), the thermoplasticcomponent 26 may assume a single layer, or may include a plurality ofindependent layers (e.g., see FIG. 3, where thermoplastic componentlayers are identified as 26 a-26 d). In those embodiments where thethermoplastic component 26 includes a plurality of different layers(e.g., multilayer extrusion, or a multilayer sheet, etc.), the materialof the specific layers and their position within the stack up of layerscan be selected to enhance one or more characteristics of the presentcomposite sheet material 10; e.g., thermal, optical, barrier, surfaceappearance, and cost characteristics. For example, a multilayerthermoplastic component 26 can be chosen to enhance the surfacecharacteristics of the matrix 14, and therefore the surfacecharacteristics of the composite sheet material 10. The thermoplasticcomponent 26 layers can be processed to provide the matrix 14 (andtherefore the composite sheet material 10) with a flat or texturedexterior surface 28 (e.g., a matte or dimpled surface, and/or a surfacethat includes three dimensional patterns, and/or one embossed withgraphic patterns, etc.). Similarly, the material(s) of the thermoplasticcomponent 26 can give, or be finished to give, the matrix 14 a flatnon-gloss appearance, or a high-gloss appearance, or anything inbetween. The thermoplastic component 26 may also be configured tofacilitate the deposition of characters or a design on the matrix 14(e.g., the characteristics of the outer layer of the thermoplasticcomponent 26 may be chosen to facilitate the printing), or thedeposition of characters or a design within the matrix 14 (e.g.,printing on a subsurface layer of the matrix 14 that is visible on thesurface). The surface characteristics can be selected to suit theintended application of the composite sheet material 10. In someembodiments, one or more bonding materials operable to ensure bondingadhesion between the independent layers can also be included between thelayers. A bonding layer may also be used to improve the bond to thesupport component 24, as well as the other side, if a cover sheet 16 isused.

The inclusion of thermoplastic materials in the matrix 14 of the presentcomposite material sheet 10 provides desirable properties that make thepresent composite sheet material 10 a favorable component for manydifferent applications. For example, the thermoplastic and supportcomponents of the present matrix provide the composite sheet materialwith excellent durability, formability, impact resistance, memory,cleanability, cosmetic improvement and toughness that is desirable inexterior applications where the composite sheet material 10 is subjectto impacts, bending loads, and environmental constraints (e.g., sun,moisture, temperature variations, etc.).

In some embodiments, the matrix 14 may include a veiling layer 40 (seeFIG. 1B) like that described above as part of the substrate 12. In otherembodiments, the support component 24 of the matrix can have a veilinglayer 40 configuration as described herein. In the embodiments where thesupport component 24 has a veiling layer 40 configuration, a primarymaterial (or combination of materials) included within the veiling layer40 has a melting point that is higher than the melting point of thethermoplastic component 26 within the matrix.

An intermediate bonding agent may be used to facilitate bonding of thematrix 14 on to the underlying substrate 12. For example, maleicanhydride may be used as an additive to one or more of the components ofthe matrix to act as a bonding agent.

Referring to FIG. 6, in some embodiments the matrix 14 may include asecondary thermoplastic component 27. The secondary thermoplasticcomponent 27 includes one or more sheets or layers of a thermoplasticmaterial that has a melting point equal to or less than the supportcomponent 24. Like the thermoplastic component 26, the secondarythermoplastic component 27 in the matrix 14 of the present compositematerial sheet 10 provides desirable properties that make the presentcomposite sheet material 10 a favorable component for many differentapplications; e.g., providing desirable durability, formability, impactresistance, memory, and toughness.

In some embodiments, the present composite sheet material 10 includes acover sheet 16 attached to the matrix 14. The cover sheet 16 may beattached in a manner that enables the cover sheet 16 to be readilyremoved; e.g., peeled off by the end user—see FIG. 4. In thoseembodiments where the cover sheet 16 is readily removable, one or bothof the two surfaces that will be in contact when the cover sheet 16 isattached (i.e., either the exposed surface 28 of the matrix 14 or theopposing surface 30 of the cover sheet 16) are non-active, therebypermitting removal of the cover sheet 16 from the matrix 14 material byhand or machine; i.e., the non-active surface prevents significantbonding (or conversely allows a limited amount of bonding) between thetwo surfaces. A paper sheet product treated with a material such asQuilon® chrome complexes, commercially available from DuPont, is anexample of a cover sheet 16 that can be lightly adhered and used as aremovable cover sheet 16. Other acceptable treatments to create anon-active cover sheet surface include one or more wax type materialsapplied to the surface of the cover sheet 16, or a fatty acid esterrelease surface, silicone, etc. The present invention is not, however,limited to any particular treatment for creating a non-active coversheet. A paper material cover sheet is advantageous relative to manymaterials for several reasons, including: 1) it will not appreciablyshrink during the formation of the composite sheet material 10; 2), itcan be preprocessed (e.g., by calendaring) to have a particular densityand/or surface finish; and 3) paper is relatively inexpensive. Someplastic materials may shrink or otherwise distort when subjected to alamination process. However, the cover sheet 16 may also be made frompolymeric materials in a form that will not shrink appreciably or atall; e.g., cast films, pre-shrunk films (e.g., pre-shrunk biaxialoriented PET), etc. Other examples of an acceptable cover sheet 16include those formed from one or more of paper (cellulosic,non-cellulosic, or other), polyamide (PA), polyphenylsulfone (PPSU),polyphenylsulfide (PPS), polyurethane (PU), polyethylene (PE),low-density polyethylene (LDPE), polyamide (PA), polyamide-imide (PAI),ionomer (e.g., sold by DuPont under the tradename of Surlyn® by DuPont),polycarbonate (PC), polyethylene terephthalate (PET), PBT,fluoropolymers (Polytetrafluoroethylene (PTFE), perfluoroalkoxy polymer(PFA), fluorinated ethylene-propylene (FEP); all of which are sold byDuPont under the tradename of Teflon® by DuPont). As indicated above, acover sheet 16 made from any of these materials may be treated tofacilitate its removal from the matrix 14. The cover sheet 16 is not,however, limited to these materials.

In some embodiments, the cover sheet 16 may comprise a shrinkablematerial (i.e., a material that dimensionally decreases to adimensionally stable state). In such embodiments, the cover sheet 16 maybe dimensionally decreased by the application of heat and/or pressure toarrive at the desired dimensions in a stable state during the process offorming the composite sheet material 10. A non-limiting example of anacceptable for material that can be used as a shrinkable cover sheet isbiaxially oriented PET (e.g., Mylar®). A shrinkable cover sheet may beused in those embodiments where the cover sheet 16 is readily removed,or permanently attached as described below.

The removable cover sheet 16 can provide one or more desirablefunctions. For example, as will be described below, the composite sheetmaterial 10 can be formed using a continuous or batch thermo-pressuremanufacturing process wherein the composite sheet material 10 issubjected to elevated surface pressure and temperature to promotelamination between the components of the composite sheet material 10.During the lamination process (e.g., the matrix 14 formation processand/or the composite material sheet 10 formation process), the surfacecharacteristics of the removable cover sheet 16 can impart surfacecharacteristics to the exterior surface of the matrix 14 portion of thecomposite sheet material 10; e.g., a removable cover sheet 16 having aflat surface can impart a flat surface onto the matrix 14, or a mattefinish, or a pebbled finish, etc. Hence, the surface characteristics(e.g., visual improvement) of the matrix 14 can be influenced ordictated by the removable cover sheet 16 rather than the characteristicsof the device (e.g., a platen or rollers) applying the pressure to thecomposite sheet material 10 during the lamination process. For example,an unexpected improvement was discovered when a two mil (i.e., 0.002inches) cover sheet of biaxially oriented PET material was used duringthe present composite sheet material forming process. Upon removal ofthe cover sheet 16, a high quality, high gloss finish (similar to a“class A” surface finish) was discovered resulting from the use of theaforesaid cover sheet 16. The removable cover sheet 16 can also be usedas a medium to transfer materials to the matrix 14. For example, theremovable cover sheet can provide an effective mechanism for applyingtransfer print to the exterior surface 28 of the matrix 14. One of theadvantages of applying transfer print via the removable cover sheet 16is that it is easier to apply the transfer material to the cover sheet(e.g., via printing) than to a formed matrix 14 or formed compositematerial sheet 10. The cover sheet 16 can also be used as a protectivecover.

In other embodiments, a cover sheet 16 may be permanently attached tothe matrix 14, and consequently the composite sheet material 10, in anon-removable manner. The coversheet that is attached to the matrix 14,and thereby incorporated into the composite sheet material 10, can beused to provide desirable surface characteristics (e.g., a flat,textured, or embossed surface), printed or otherwise producedcharacters, designs, or graphics, or pigmentation, and/or a desirablesurface finish (e.g., a flat non-gloss appearance, a high-glossappearance, or anything in between). A bonding agent may be used tofacilitate bonding of the cover sheet 16 to the underlying matrix 14.The bonding agent may be applied to one or both surfaces of the coversheet and the matrix (or included as an additive as indicated above)that will be in contact with one another. The non-removable cover sheet16 can be made from any of the cover sheet materials listed above. Thecover sheet 16 may also include one or more additives, including thosethat function as ultraviolet (UV) inhibitors and thermal stabilizers,those that make the cover sheet 16 fire-resistant, and other additivessuch as pigments, PTFE and other fluoropolymers to improve stainresistance and cleanability, wetting agents, anti-microbial agents,anti-gas fade agents (e.g., chemical resistance agents), hydrophilicagents, and hydrophobic agents. The cover sheet 16 may also include oneor more additives, including those that function as ultraviolet (UV)inhibitors and thermal stabilizers, those that make the composite sheetmaterial 10 fire-resistant, and other various additives such aspigments, silicones, additives that improve stain resistance andcleanability (e.g., PTFE and other fluoropolymers), wetting agents,anti-microbial agents, anti-gas fade agents (e.g., chemical resistanceagents), hydrophilic agents, hydrophobic agents. In those embodimentswhere the cover sheet 16 is extruded, the cover sheet 16 may alsoinclude process aids to improve extrusion surface uniformity. The coversheet 16 may also include one or more of the following additives:biodegradable additives, grease resistant additives, antioxidantadditives, slip agents, additives to minimize or eliminate staticelectricity, and conductive and/or semi-conductive particles or fibers.The characteristics (e.g., fire-resistance, UV inhibitors, etc.) of thevarious additives and components described above as potentialconstituents within the cover sheet 16, are not limited to the coversheet 16, but may also be described as being a part of the compositesheet material 10 of which the cover sheet 16 is a portion.

In some embodiments, one or more layers 34 of thermoplastic material maybe applied (e.g., by extrusion) to a surface 30 of the coversheet 16 toform a coversheet laminate 36. The layer 34 of thermoplastic materialmay comprise the materials described above regarding the thermoplasticcomponent 26 of the matrix 14; e.g., configurations of the followingmaterials (and co-polymers thereof) having a melting point lower thanthat of the support component 24 material: polypropylene (PP),polyethylene (PE), polyethylene terephthalate (PET), low-densitypolyethylene (LDPE), polyurethane (PU), polyamide (PA), polyamide-imide(PAI), ionomer (e.g., Surlyn®, Surlyn Reflections®—which is an ionomerwith a polyamide—, etc.), acrylic, metallocenes (i.e., a type ofthermoplastic material), etc., and additives, including those thatfunction as ultraviolet (UV) inhibitors and thermal stabilizers, thosethat make the composite sheet material 10 fire-resistant, and othervarious additives such as pigments, silicones, additives that improvestain resistance and cleanability (e.g., PTFE and other fluoropolymers),wetting agents, anti-microbial agents, anti-gas fade agents (e.g.,chemical resistance agents), hydrophilic agents, hydrophobic agents,biodegradable additives, grease resistant additives, antioxidantadditives, slip agents, additives to minimize or eliminate staticelectricity, and conductive and/or semi-conductive particles or fibers.

In these embodiments, the coversheet 16 may be formed using thematerials described above; e.g., a paper sheet product treated with amaterial such as Quilon® chrome complexes, a non-active cover sheetsurface including one or more wax type materials applied to the surfaceof the cover sheet 16, etc. In addition, however, the coversheet 16 maybe formed from a biaxially oriented polyester film (BOPET) commonlyknown as trade names Mylar®, Melinex®, Lumirror®, and Hostaphan®. Itcould also be biaxially oriented polyamide film (BOPA) such as Biaxis®,or any other suitable thermally and physically stable web.

The coversheet laminate 36 may also include a support component 38 thesame as or similar to that described above regarding the supportcomponent 24 of matrix 14; i.e., including a material (or combination ofmaterials) having a melting point that is higher than the melting pointof the one or more layers 34 of thermoplastic material. Specificexamples of support component 24 materials, which can be used forsupport component 38, are described above. An additional example of anacceptable material for the support component 38 is a needle punchednon-woven material including a higher temperature melt fiber componentand a lower temperature melt fiber component. The higher temperaturemelt component has a melting temperature that is higher than that of thelower temperature melt component. It is our experience that aneedle-punched non-woven support component 38 having a basis weight inthe range of about two to five ounces per square yard (i.e., 2-5oz/sq.yd) works well. An example of a support component 38 is asubstrate having about 50% higher temperature melt fibers consisting ofpolyester fibers and about 50% lower temperature melt fibers consistingof polypropylene fibers. As indicated above, the support component 38 isnot limited to this example. In some embodiments, the support component38 may include a bicomponent nonwoven having two different polymersarranged within a web. A preferred bicomponent nonwoven is a continuousfilament spunbond type bicomponent non-woven. Bicomponent nonwovensutilize a sheath and core construction, wherein a core filament made ofone resin is completely surrounded by a sheath of a different resin.Many polymer materials can be used in a bicomponent nonwoven, includingbut not limited to, polyester, polypropylene, polyethylene, nylon, andpolylactic acid. An example of an acceptable bicomponent nonwoven is onehaving polypropylene or polyethylene sheath and a polyester core.

In the above embodiments of a coversheet laminate 36, the one or morelayers 34 of thermoplastic material are applied to the coversheet 16prior to the coversheet laminate 36 being combined with the matrix 14 ina manner described herein. In those coversheet laminate 36 embodimentsthat include a support component 38, the support component 38 may beadded to the coversheet laminate 36 that includes the one or more layers34 of thermoplastic material applied to the coversheet 16

An example of how the coversheet laminate 36 can be formed is shown inFIG. 7. As shown in FIG. 7, a layer 34 of thermoplastic material may beapplied to a surface 30 of a coversheet 16 by extruding the layer 34 onto the coversheet 16, and subsequently passing the layer 34 andcoversheet through a calendaring-type nip formed between a first roller42 and a second roller 43, to form a version of the coversheet laminate36 having a single layer 34 of thermoplastic laminate applied to thecoversheet 16. In those embodiments of the coversheet laminate 36 thatuse only a single layer 34 of thermoplastic material, that layer may beapplied in a thickness adequate to provide desirable veilingcharacteristics for the application at hand. In those embodiments of thecoversheet laminate 36 that use more than one layer 34 of thermoplasticmaterial, the layers may have a collective thickness adequate to providedesirable veiling characteristics for the application at hand. The firstroller 42 and the second roller 43 may be chilled, heated or ambient,including combinations thereof, to facilitate processing of thematerials/layers into the coversheet laminate 36.

An example of how another embodiment of the coversheet laminate 36 canbe formed is shown in FIG. 8. As shown in FIG. 8, a second layer ofthermoplastic material (referred to here as layer 34A for clarity sake;or other suitable bonding agent such as adhesive scrims, tapes, glues,etc., that would permanently bond support layer 38 to coversheetlaminate 36) is applied to the coversheet laminate 36 formed in aprocess such as is described in FIG. 7. In alternative embodiments, thematerial 34A could take the form of other materials (e.g., an adhesivescrim, tape, glue, etc., operable to bond coversheet laminate 36 tosupport layer 38) in place of a second layer of thermoplastic material.In addition, a support component 38 is added to form a coversheetlaminate (referred to here as laminate 36A for clarity sake) thatincludes coversheet laminate 36, a second layer 34A of thermoplasticmaterial, and support component 38. The formation of the coversheetlaminate 36A embodiment shown in FIG. 8 includes extruding the secondlayer 34A of thermoplastic material (or provision of other materialoperable to bond the coversheet 36 to the support layer 38 as describedabove) on to the thermoplastic material surface of laminate 36, andsubsequently passing the laminate 36, layer 34A, and support component38 through a calendaring-type nip formed with a first roller 42 andsecond roller 43, to form the coversheet laminate 36A. The positions ofthe laminate 36, layer 34A, and support component 38 relative to the nipas shown in FIGS. 7 and 8 are for illustrative purposes only, and theprocess is not limited to these relative positions. In an alternativeembodiment, a suitable bonding agent such as an adhesive scrim, tape,glue, etc., could also be used to adhere the layers 34 and 34A together.

An example of how another embodiment of the coversheet laminate 36 canbe formed is shown in FIG. 9. As shown in FIG. 9, on or more layers 34of thermoplastic material may be applied to a surface 30 of a coversheet16 by extruding the layers 34 on to the coversheet 16. The layers 34 andcoversheet 16, and a support component 38 are subsequently passedthrough a calendaring-type nip formed by a first roller 42 and a secondroller 43, to form a coversheet laminate version 36B having a one ormore layers 34 of thermoplastic laminate applied to a coversheet 16, anda support component attached to the surface of the layers 34 oppositethe coversheet 16.

The present invention is not limited to these examples (including thosereferred to above as 36A and 36B for description clarity) of coversheetlaminate 36. In addition, the coversheet laminate 36 is not limited toany of the component materials described above; i.e., any of thecoversheet 16, support component 38, and the layer 34 materialsdescribed above. These coversheet laminate 36 embodiments cansubsequently be included in the composite sheet material 10 describedherein in place of a coversheet 16.

In addition, the coversheet 16 component included in the coversheetlaminate 36 may be attached to the thermoplastic layer(s) 34 in a manner(i.e., lightly adhered) that allows the coversheet 16 to be readilyremoved after the composite sheet material 10 is formed (as describedherein), or in a manner such that the coversheet 16 is intended to bepermanently attached to the thermoplastic layer(s) 34 as describedherein.

In the embodiments having a coversheet laminate 36, the cover sheet 16may comprise a shrinkable material (i.e., a material that dimensionallydecreases to a dimensionally stable state); e.g., the cover sheet 16 maybe dimensionally decreased by the application of heat and/or pressure toarrive at the desired dimensions in a stable state during the process offorming the composite sheet material 10. Examples of acceptabledimensionally stable coversheet 16 materials are provided above. Thedimensionally stable cover sheet 16 will substantially dimensionallystabilize the coversheet 16 and decrease the possibility that thecoversheet 16 will dimensionally change during the formation of thecomposite sheet material 10. The dimensionally stable cover sheet 16will likely also make the coversheet laminate 36 easier to handle andimprove the surface quality; e.g., by eliminating wrinkles.

The coversheet laminate 36 embodiments provide substantial improvementsin the surface finish of the composite sheet material 10. It is believedthat the improvements in the surface finish may be the product of thethermoplastic layer(s) 34 thermally forming on the surface of thecoversheet 16 prior to forming the composite sheet material 10. Thesurface qualities of the coversheet 16 imprint on the layer 34 of thethermoplastic material, which is cooled to some degree prior toformation of the composite sheet material 10. If, for example, a glossysurface finish is desired, a high quality uniform surface material canbe used as the coversheet 16 material, which material would then impartgloss to the cooled later 34 of thermoplastic material. Different layer34 surface finishes could be produced by using a coversheet 16 having adifferent surface finish; e.g., matte, satin, textured, embossed, etc.If the coversheet is printed or coated, the print image or coating couldalso be designed to transfer to the layer 34 of thermoplastic material.The coversheet laminate 36 processing shown in FIGS. 7 and 8 (andpossibly FIG. 9, depending on the timing of when the support layer 38 isadded), which allows the thermoplastic layer(s) 34 to thermally form(e.g., assume a configuration closer to a solid than when first appliedto the surface of the coversheet 16) prior to further processing (e.g.,addition of the support layer 38 or formation of the composite sheetmaterial 10), is understood to allow the layer of thermoplastic material34 to form to some degree prior to further processing. As a result, thesurface characteristics (e.g., its flatness) and its ability to act as aveiling layer are improved. For example, in the processing embodimentsshown in FIGS. 7 and 8, the surface of the coversheet laminate 36opposite the coversheet 16 are contacted by the first roller 42, whichroller may have a finish (e.g., shiny, matted, etc.) that impartssurface characteristics to the layer 34 that can favorably influence thesurface characteristics (e.g., flatness) of the composite sheet material10.

The coversheet laminate 36 (36A, 36B) can be produced at a time earlierthan the formation of the composite sheet material 10; e.g., produced,stored, and subsequently included in the formation of the compositesheet material 10. Alternatively, the coversheet laminate 36 (36A, 36B)can be produced as part of a continuous process of forming the compositesheet material 10; e.g., produced upstream in a continuous process offorming the composite sheet material 10.

In some embodiments, the composite sheet material 10 may include abacking layer 18 that is attached to the second face surface 22 of thesubstrate 12. The backing layer 18 may include a plurality of differentmaterials. For example, the backing layer 18 may include a woven ornonwoven material; e.g. a non-woven material having a weight in therange of approximately 1.5 to 5.0 ounces per square yard. The presentinvention is not limited, however, to such a backing layer. Aparticularly desirable backing material is one that includes a spunlacedor needle punched non-woven material (e.g., PET, nylon, fiberglass,etc.), which spunlaced or needle punched non-woven material hasomnidirectionally oriented fibers that help to provide omnidirectionalstrength characteristics that decrease the chance of delaminationoccurring; (e.g., fibers oriented in any of the X, Y, and Z axes, andcombinations thereof; examples of the spunlaced and needle punchedprocesses are described above). In alternative embodiments, the backinglayer 18 may take the form of an apertured fabric (sometimes referred toas “perforated fabric”), which type of material is described above. Anadvantage of using an apertured nonwoven is that it can provide asuperior bonding surface (to both exposed surfaces) due to additionalsurface area provided by the apertures. The backing layer 18 may also beformed using fibers that are pretreated, coated, or saturated with abinder to provide the backing layer 18 with desirable properties.Alternatively, the fibers within the nonwoven may be subsequentlytreated, coated or saturated with the binder to provide the aforesaiddesirable properties. Non-limiting examples of such a binder include apolyurethane (e.g., BASF Astacin®), butadiene (e.g., BASF Luron®), or anacrylic that is a dispersion mainly of polyacrylic and polymethacrylicesters, usually produced by radical initiated emulsion polymerization ofthe unsaturated monomers (e.g., Celanese Emulsions Nacrylic® 217A, whichis a self-crosslinking acrylic polymer emulsion, or Celvol 523) can beused to further enhance adhesion within and strength of the backinglayer 18. The embodiments of the backing layer 18 that use a binder arenot, however, limited to these examples. In some embodiments, thebacking layer 18 may include a bicomponent nonwoven having two differentpolymers arranged within a web. A preferred bicomponent nonwoven is acontinuous filament spunbond type bicomponent non-woven. Bicomponentnonwovens utilize a sheath and core construction, wherein a corefilament made of one resin is completely surrounded by a sheath of adifferent resin. Many polymer materials can be used in a bicomponentnonwoven, including but not limited to, polyester, polypropylene,polyethylene, nylon, and polylactic acid. An example of an acceptablebicomponent nonwoven is one having polypropylene or polyethylene sheathand a polyester core. In some embodiments, the backing layer 18 may alsobe calendered to increase density and flatness, and/or to facilitatebonding of the fibers together to increase the resistance todelamination as well as improve adhesion to the second face surface 22of the substrate 12. The backing layer can act as a mechanism forattaching the present composite sheet material 10 to structuralmaterials such as wood, aluminum, steel, foam, composites, etc.

As indicated above, the matrix 14 and composite sheet material 10 may beformed using a variety of different manufacturing techniques.

Referring to FIG. 3, in a first example of a method for producing thepresent composite sheet material 10, the substrate 12 and matrix 14 canbe produced independent of one another. The matrix 14 is formed byapplying a multilayer coating of thermoplastic component 26 onto thesupport component 24 to form the matrix 14. The multiple layers ofthermoplastic component 26 may be applied by a multilayer extrusionprocess, wherein each layer is extruded onto the support component 24.Each extruded layer of the thermoplastic component 26 may have the sameor different characteristics (e.g., different layers having differentmelt points, etc.). One or more bonding agents may be disposed betweenthe layers to facilitate relative attachment within the matrix 14, andalso to facilitate attachment of the matrix 14 to the underlyingsubstrate 12. The composite sheet material 10 can then be formed in themanner described above; e.g., using a continuous or batch-typethereto-pressure process where the processing temperature for thecomposite sheet material 10 is selected to be greater than the meltingpoint of the thermoplastic component 26 of the matrix 14, but less thanthe melting point of the support component 24 of the matrix 14. In thisembodiment, the layers of the thermoplastic component 26 are laminatedtogether, and some amount of the one or more layers closest to thesupport component 24, or some portion of all the layers, will migratethrough the support component 24 into contact with the substrate 12.

In a second example of a method for producing the present compositesheet material 10, the substrate 12 and matrix 14 can be producedindependent of one another, with the substrate 12 formed as indicatedabove. In this example, the matrix 14 includes a thermoplastic component26 in sheet form disposed on one side of the support component 24; e.g.,also in sheet form. FIG. 4 shows a diagrammatic exploded view of thestack up of the thermoplastic component 26, the support component 24,and the substrate 12, prior to lamination to illustrate the relativepositions. Depending upon the specific process, the thermoplasticcomponent sheet 26 and the support component sheet 24 may be attached toone another to form the matrix 14 and to facilitate handling; e.g.,attached using a thermo-pressure process, or adhesives, etc. Thecomposite sheet material 10 can then be formed by attaching the matrix14 to the substrate 12 using a continuous (e.g., roller-type dynamicprocess) or batch-type (e.g., platen-type static process)thermo-pressure process in which a surface of the support component 24portion of the matrix 14 is disposed contiguous with the first facesurface 20 of the substrate 12, and the stack up of the substrate 12 andcomponent sheets 24,26 of the matrix 14 are subjected to an elevatedpressure and temperature during the lamination process. As indicatedabove, the formation temperature of this second thermo-pressure bondingprocess is selected to be greater than the melting point of thethermoplastic component 26 of the matrix 14, but less than the meltingpoint of the support component 24 of the matrix 14. The elevatedtemperature and pressure causes some amount of the thermoplasticmaterial to melt and migrate and contact the first face surface 20 ofthe substrate 12, causing the matrix 14 to be attached to the substrate12. As indicated above, a bonding agent may be disposed between thesubstrate 12 and the matrix 14 to facilitate the attachment of thematrix 14 on to the underlying substrate 12.

In a third example of the method for producing the present compositesheet material 10, the substrate 12 and matrix 14 may be producedindependent of one another, with the substrate 12 formed as indicatedabove. In this example, the matrix 14 includes a multilayerthermoplastic component 26 in sheet form disposed on one side of thesupport component 24, which is also in sheet form. Each layer of thethermoplastic component 26 may have the same or differentcharacteristics (e.g., different layers having different melt points,etc.). The multiple layers of thermoplastic component 26 may be adheredto one another to facilitate handling or they may be stacked relative toone another without being adhered to one another. The composite sheetmaterial 10 can then be formed by attaching the matrix 14 to thesubstrate 12 in the manner described above; e.g., using a continuous orbatch-type thermo-pressure process where the processing temperature forthe composite sheet material 10 is selected to be greater than themelting point of the thermoplastic component 26 of the matrix 14, butless than the melting point of the support component 24 of the matrix14. In the event a continuous thermo-pressure process is used to formthe composite sheet material 10, the multiple layers of thethermoplastic component 26 may not be literally “stacked” prior toprocessing but rather may all be fed into the continuous typethermo-pressure processor to form the sheet material 10 at the beginningof the process line, or at defined positions along the processing axisof the processor. In similar fashion, other constituents of thecomposite sheet material (e.g., the substrate 12, a backing layer 18,etc.) may also be fed into the continuous type thermo-pressure processorfrom the same or different positions along the processing axis of theprocessor. In these embodiments, the layers of the thermoplasticcomponent 26 bond together during the lamination process, and someamount of the one or more layers closest to the support component 24, orsome portion of all the layers, will migrate through the supportcomponent 24 into contact with the substrate 12.

Referring to FIG. 5, in a fourth example of a method for producing thepresent composite sheet material 10, the substrate 12 and matrix 14 areformed using any of the above described methods. In this example, aremovable cover sheet 16 is disposed contiguous with the surface of thematrix 14 opposite the substrate 12; e.g., the stack up of compositesheet material 10 components includes substrate 12, support component24, thermoplastic component 26, and cover sheet 16, in that order priorto formation of the composite sheet material 10 via the methodsdescribed above. During formation of the composite sheet material 10,the cover sheet 16 may be operable to impart surface characteristics tothe matrix 14 and/or may be operable to transfer one or more materialsto the exterior surface 28 of the matrix 14. In some embodiments, theremovable cover sheet 16 is adhered to the matrix 14 in a manner thatallows the cover sheet 16 to be maintained on the composite sheetmaterial 10. After formation of the composite sheet material 10, thecover sheet 16 may be maintained on the composite sheet material 10 as aprotective covering and can be readily removed upon use. FIG. 5diagrammatic shows an edge of the cover sheet 16 peeled up to illustratethat it may be readily removed.

In a fifth example of a method for producing the present composite sheetmaterial 10, the substrate 12 and matrix 14 are formed using any of theabove described methods. In this example, a non-removable cover sheet 16is disposed contiguous with the surface of the matrix 14 opposite thesubstrate 12; e.g., the stack up of composite sheet material 10components includes substrate 12, support component 24, thermoplasticcomponent 26, and cover sheet 16, in that order prior to formation ofthe composite sheet material 10. In some embodiments, a bonding agentoperable to ensure bonding adhesion between the cover sheet 16 and thematrix 14 may be used. The composite sheet material 10 can then beformed using any of the methods described above.

Referring to FIG. 6, in a sixth example of a method for producing thepresent composite sheet material 10, the substrate 12 and matrix 14 areformed using any of the above described methods. In this example, thematrix 14 also includes a secondary thermoplastic component 27 thatincludes one or more sheets of a thermoplastic material that has amelting point equal to or less than the support component 24. Asindicated above, the secondary thermoplastic component 27 providesdesirable properties that make the present composite sheet material 10 afavorable component for many different applications; e.g., desirabledurability, formability, impact resistance, memory, and toughness. Inthis example, the stack up of the composite sheet material componentsincludes a cover sheet 16 disposed contiguous with the surface of thematrix 14 opposite the substrate 12 (e.g., contiguous with the secondarythermoplastic component 27), the thermoplastic component 26, the supportcomponent 24, and the substrate 12, in that order prior to formation ofthe composite sheet material 10 via the methods described above. Duringformation of the composite sheet material 10, the thermoplasticcomponent 26 within the matrix bonds with the secondary thermoplasticcomponent 27, and migrates through the support component and bonds withthe substrate 12.

The above examples of composite sheet materials 10 according to thepresent invention are provided to illustrate specific embodiments of thepresent invention composite sheet materials 10. The present compositesheet material is not limited to these examples however.

One of the advantages of the present composite sheet material 10 is thatthe it avoids appearance issues associated with the substrate 10 andthereby increases the number of possible uses for the product. Theconstituents within the substrate 10 can give the substrate 10 anundesirable rough surface; i.e., a surface with a poor level offlatness. The matrix 14 of the present composite sheet material acts asa veil that prevents the rough surface or patterns or undesirableblemishes of the substrate 10 from telegraphing through to the exposedsurface of the composite sheet material. As a result, the surfacecharacteristics of the composite sheet material are dictated by thematrix 14, and not by the substrate 10. In addition, the matrix 14 canbe formulated to provide other significant functions; e.g.,environmental protections including anti-microbial, fire-resistance,chemical resistance, UV light inhibition, abrasion/scratch resistance,cleanability, and others, as well as decorative or informational colors,printing, etc.

The above described composite sheet material 10 can be formed to have amulti-directional grain structure that has desirable physical andmechanical properties and economic advantages versus competingtechnologies such as thermoset FRP, steel, aluminum, plywood, etc. Thecomposite structure can be formed in several different configurationsand thicknesses to suit a large variety of applications. The thicknessof the composite structure is typically a function of the number oflayers forming the material. Composite structures utilizing the presentcomposite sheet material 10 can be used, for example, in transportationapplications to make cargo containers, walls, ceilings, doors, roofing,sub-pan liners, and scuff liners in tractor trailers, dry-freight orrefrigerated. In addition, composite structures utilizing the presentcomposite sheet material 10 are very well suited for use as antransportation aerodynamic improver, such as a side skirt disposedunderneath a tractor-trailer body. The composite structures utilizingthe present composite sheet material 10 as an exterior layer haveexcellent durability and impact resistance, and stand up well tofork-lift abuse, shifting cargo, and other abuse, and allow fleets toreduce operating costs in both materials requirements and downtimeresulting from interior damage. The present composite sheet material 10can also be used in building material applications; e.g., walls, panels,ceilings, etc.

The following application examples illustrate the utility of the presentcomposite sheet material. As a first example, a pair of side skirtassemblies incorporating the present composite sheet material 10 may beconfigured for attachment under a tractor trailer, between the wheels ofthe truck tractor and the wheels of the tractor trailer. The side skirtassemblies may be configured to have a length, a width, a thickness, andmay be attached to a support frame. The support frame may be bonded orotherwise attached to the side of the substrate 12 opposite the sideattached to the matrix 14, or attached to backing layer 18 which isbonded or otherwise attached to the side of the substrate 12 oppositethe side attached to the matrix 14. Examples of support frames (e.g.,struts) are disclosed in U.S. Pat. Nos. 7,887,120 and 7,942,469, each ofwhich is hereby incorporated by reference in its entirety into thepresent application. The support frame may be used to mount the sideskirt assembly onto the tractor trailer. The side skirt assemblies aretypically attached and oriented so that the width of each side skirtassembly is substantially vertically positioned on each side of the roadtrailer 20, and the length of the side skirt assemblies extend along thelength of the tractor trailer. The side skirt assemblies divert airaround the tractor trailer and reduce the air drag created by thetractor trailer during operation. As indicated above, the presentcomposite sheet material 10 is operable to be printed on, or otherwisedecorated; e.g., advertisements, logos, etc. Additional examples of theutility of the present composite sheet material 10 include applicationswherein the composite sheet material 10 is configured to be used as oneor more of the walls, ceiling, doors, and roofing of a tractor trailerhaving an enclosed box style container, or scuff liners attached to thewalls or ceilings of the box container, or wall or ceiling surfaceswithin public transportation vehicle such as a bus, train, or airplane,etc. In these applications, panels formed from the present compositesheet material may be attached to a frame defining the box container, orvehicle interior or exterior. The above examples are illustrative of theuses of the present composite sheet material, but are not intended tolimit the applications in which the composite sheet material 10 may beused.

Although this invention has been shown and described with respect to thedetailed embodiments thereof, it will be understood by those skilled inthe art that various changes in form and detail thereof may be madewithout departing from the spirit and the scope of the invention. Forexample, the present composite material substrate and method for formingthe same is described herein in terms of various embodiments includingdifferent elements or manufacturing steps. The identified embodiments,elements, and steps may be utilized singularly or in combination withany of the other embodiments, elements, and steps. In addition, itshould be noted that FIGS. 1-6 are drawn to diagrammatically illustrateaspects of the present invention, and are not necessarily drawn toscale.

What is claimed is:
 1. A composite sheet material, comprising: asubstrate having a first face surface, a second face surface, and aplurality of edges; a support layer having a support layer material thathas a first melting point; and a thermoplastic layer having athermoplastic layer material that has a second melting point less thanthe first melting point; and a coversheet laminate that includes acoversheet and a thermoplastic material layer applied to the coversheet,wherein the thermoplastic layer is adjacent to the support layer, thethermoplastic layer is migrated into the support layer, thethermoplastic layer and the support layer together provide a laminate, apercentage amount of the thermoplastic layer material at a first side ofthe laminate is greater than a percentage amount of the thermoplasticlayer material at a second, opposing side of the laminate, thethermoplastic layer includes one or more polymeric materials selectedfrom the group consisting of polypropylene, polyethylene, polyethyleneterephthalate, low-density polyethylene, polyurethane, polyamide,polyamide-imide, ionomer, acrylic, combinations thereof, and co-polymersthereof, and the support layer includes one or more materials selectedfrom the group consisting of polyester, polyamide, polyphenylsulfide,aromatic polyamide, fiberglass, polytetrafluoroethylene, wool, carbonfiber, alumina, silica, polyimide, polypropylene, polyethylene,cellulose, rayon, viscose, and combinations thereof.
 2. The compositesheet material of claim 1, wherein the cover sheet is adhered to thethermoplastic material layer in a manner that allows removal of thecover sheet from the thermoplastic material layer post formation.
 3. Thecomposite sheet material of claim 2, wherein the cover sheet comprises apaper material having a cellulosic material, and which cover sheet istreated with a material to impede bonding of the cover sheet to thethermoplastic material layer.
 4. The composite sheet material of claim2, wherein the coversheet comprises one or more polymeric materialsselected from the group consisting of polyphenylsulfone,polyphenylsulfide, polyurethane, polyethylene, low-density polyethylene,polyamide, polyamide-imide, ionomer, polycarbonate, polyethyleneterephthalate, polybutylene terephthalate, fluoropolymers, andco-polymers thereof.
 5. The composite sheet material of claim 1, whereinthe cover sheet laminate is permanently bonded to the laminate.
 6. Thecomposite sheet material of claim 1, wherein the coversheet laminateincludes a plurality of thermoplastic material layers.
 7. The compositesheet material of claim 1, wherein the substrate further comprises aveiling layer disposed between the substrate and the laminate.
 8. Thecomposite sheet material of claim 1, wherein the laminate furthercomprises a veiling layer.
 9. The composite sheet material of claim 8,wherein the veiling layer includes a higher temperature melt fibercomponent and a lower temperature melt fiber component.
 10. Thecomposite sheet material of claim 9, wherein the higher temperature meltfibers and the lower temperature melt fibers are distributed within theveiling layer.
 11. The composite sheet of claim 1, wherein the supportlayer includes a needle-punched non-woven material.
 12. The compositesheet of claim 1, wherein the support layer includes a bicomponentnon-woven material.
 13. A method of forming a composite sheet material,comprising the steps of: providing a substrate having a first facesurface, a second face surface, and a plurality of edges; forming alaminate from a sheet of a support component and a sheet of athermoplastic component, wherein a support component material of thesupport component has a first melting point, a thermoplastic componentmaterial of the thermoplastic component has a second melting point, andthe second melting point is less than the first melting point;positioning the substrate and the laminate such that the laminate iscontiguous with the first face surface of the substrate; and laminatingthe substrate and laminate together in a thermo-pressure process to formthe composite sheet material, wherein the thermoplastic component isadjacent to the support component, the thermoplastic component ismigrated into the support component, a percentage amount of thethermoplastic component material at a first side of the laminate isgreater than a percentage amount of the thermoplastic component materialat a second, opposing side of the laminate, the thermoplastic componentincludes one or more polymeric materials selected from the groupconsisting of polypropylene, polyethylene, polyethylene terephthalate,low-density polyethylene, polyurethane, polyamide, polyamide-imide,ionomer, acrylic, combinations thereof, and co-polymers thereof, and thesupport component includes one or more materials selected from the groupconsisting of polyester, polyamide, polyphenylsulfide, aromaticpolyamide, fiberglass, polytetrafluoroethylene, wool, carbon fiber,alumina, silica, polyimide, polypropylene, polyethylene, cellulose,rayon, viscose, and combinations thereof.
 14. The method of claim 13,further comprising the steps of: providing a cover sheet that impartsone or more surface characteristics to the composite sheet materialduring thermo-pressure formation of the composite sheet material; andpositioning the cover sheet on a side of the laminate that is oppositethe side contiguous with the substrate; and subjecting the cover sheetto the thermo-pressure process within the laminating step.
 15. Themethod of claim 14, wherein after lamination the cover sheet is adheredto the laminate in a manner that allows removal of the cover sheet fromthe laminate post formation.
 16. The method of claim 14, wherein thelaminating step causes the cover sheet to be permanently bonded to thelaminate.
 17. The method of claim 13, wherein the support componentincludes a bicomponent non-woven material.
 18. The method of claim 13,wherein at least one of the substrate and the laminate includes aveiling layer.
 19. A method of forming a composite sheet material,comprising the steps of: providing a substrate having a first facesurface, a second face surface, and a plurality of edges; forming alaminate having a support component and a thermoplastic component,wherein a support component material of the support component has afirst melting point, a thermoplastic component material of thethermoplastic component has a second melting point, and the secondmelting point is less than the first melting point; providing acoversheet laminate that includes a coversheet and a thermoplasticmaterial layer applied to the coversheet prior to the coversheetlaminate being combined with the laminate; positioning the substrate andthe laminate such that the laminate is contiguous with the first facesurface of the substrate, and positioning the coversheet laminate on aside of the laminate that is opposite the side contiguous with thesubstrate; and laminating the substrate, laminate, and coversheetlaminate together in a thermo-pressure process to form the compositesheet material, wherein the thermoplastic component is adjacent to thesupport component, the thermoplastic component is migrated into thesupport component, a percentage amount of the thermoplastic componentmaterial at a first side of the laminate is greater than a percentageamount of the thermoplastic component material at a second, opposingside of the laminate, the thermoplastic component includes one or morepolymeric materials selected from the group consisting of polypropylene,polyethylene, polyethylene terephthalate, low-density polyethylene,polyurethane, polyamide, polyamide-imide, ionomer, acrylic, combinationsthereof, and co-polymers thereof, and the support component includes oneor more materials selected from the group consisting of polyester,polyamide, polyphenylsulfide, aromatic polyamide, fiberglass,polytetrafluoroethylene, wool, carbon fiber, alumina, silica, polyimide,polypropylene, polyethylene, cellulose, rayon, viscose, and combinationsthereof.
 20. The method of claim 19, further comprising the step of:providing at least one of the substrate and the laminate with a veilinglayer.
 21. The method of claim 20, wherein the veiling layer includes ahigher temperature melt fiber component and a lower temperature meltfiber component.
 22. The method of claim 19, wherein the step ofproviding a coversheet laminate includes forming the coversheet laminatein a process independent of forming the laminate.
 23. The method ofclaim 19, wherein the composite sheet material is formed in a continuousprocess, and the coversheet laminate is provided earlier in time duringthe continuous process than the step of positioning the substrate,laminate, and coversheet laminate relative to one another during thecontinuous process.
 24. The method of claim 19, wherein the supportcomponent includes a bicomponent non-woven material.